The present invention relates to a lever fitting type power supply circuit breaking apparatus capable of attaching one of connector housings to the second connector housing and detaching the one of connector housings from the other by utilizing a cam mechanism to thereby operate a lever with a low operating force.
For example, in an electric vehicle, the capacity of a power supply, which is a battery, is large, as compared with that of a power supply in a gasoline-engine car. Thus, when the maintenance of an electric system of the electric vehicle is performed, a power supply circuit is disconnected by a circuit breaking apparatus. Consequently, the safety of an operation is ensured. Such a related power supply circuit breaking apparatus disclosed in JP-A-10-144186 is illustrated in FIGS. 23 to 30.
As shown in FIGS. 23 to 26, the circuit breaking apparatus 100 comprises an apparatus body 101 and a detachable plug 102 detachably provided in the apparatus body 101. The breaker body 101 has a pair of male terminals 103. One of this pair of male terminals 103 is electrically connected to a load. The other male terminal 103 is electrically connected to a power supply through a fuse 104. A pair of perpendicular guide wall portions 106 each having a cam groove 105 are provided outside the pair of male terminals 103, and 103, respectively.
As illustrated in FIG. 26, a reed switch 107a is provided in the apparatus body 101. The continuity or non-continuity state of the power supply circuit is detected according to ON state or OFF state of this reed switch 107a. As shown in FIGS. 23 and 26, bolt mounting holes 108 are provided at appropriate places in the apparatus body 101. The apparatus body 101 is fixed to a mounting face (not shown) by bolts (not shown) inserted into these bolt mounting holes 108.
The detachable plug 102 has an operating lever 110, on both side faces of which a pair of cam projections 109 are provided, a plug body 112 rotatably provided on this operating lever 110 through a support shaft 111, and a pair of female terminals 114, and 114 connected by a bus bar 113 to each other. Magnets 107b are embedded at laterally symmetrical places in the operating lever 110.
When an operator grasps the operating lever 110 of the detachable plug 102 and adjusts the pair of cam projections 109 and 109 to a pair of cam grooves 105, and 105 and then inserts the projections 109 and 109 from a position, which is indicated by solid lines in FIG. 25, into the grooves 105, and 105, respectively, in a position indicated by phantom lines in this figure, the male terminals 103 are inserted into the female terminals 114 and 114 in an insertion stroke of the detachable plug 102. As illustrated in FIG. 24, the pair of male terminals 103, and 103 are electrically connected to each other through the pair of female terminals 114, and 114, and the bus bar 113. Thus, the power supply circuit is brought into a continuity state. After the detachable plug 102 is inserted into the apparatus body 101, the operating lever 110 is rotated with respect to the plug body 112 from the position indicated by the phantom lines in FIG. 25 to the position indicated by the solid lines therein. Thus, as illustrated in FIG. 26, the operating lever 110 is pushed over sideways on the apparatus body 101. The magnet 107b approaches and faces the reed switch 107a just before this operating lever 110 is pushed over sideways. Thus, the reed switch 107a is turned on. Consequently, it is electrically detected that the power supply circuit is put into a continuity state.
Further, to put the power circuit into a circuit-broken state, the operating lever 110 having been pushed over sideways is turned until the state of the lever 101 is put into an erect state. Then, the detachable plug 102 attached to the apparatus body 101 is upwardly pulled out therefrom. Then, the pair of female terminals 114 and 114 are detached from the pair of male terminals 103 and 103 in a stroke in which the detachable plug 102 is upwardly pulled out from the apparatus body 101. Thus, the connection between the pair of male terminals 103, and 103 is interrupted. Consequently, the power supply circuit is brought into a broken state.
Next, the circuit conducting operation is described hereinbelow with reference to FIGS. 27 to 30. As illustrated in FIG. 27, when each of the cam projections 109 of the operating lever 110 is adjusted to the corresponding cam groove 105, and the detachable plug 102 is inserted into the apparatus body 101, an operator sometimes turns the operating lever 110 according to the misunderstanding that the plug 102 is completely inserted into the body 101, though the plug 102 is not quite completely inserted thereinto, as illustrated in FIG. 28. In such a case, as illustrated in FIG. 29, the cam projection 109 rotates together with the operating lever 110 and then abuts against the top face of the cam groove 105. When the operating lever 110 is rotated still more from the position thereof having been in this state, an external force downwardly acts upon the operating lever 110 according to the leverage principle. The detachable plug 102 is gradually inserted thereinto by this external force.
As illustrated in FIG. 30, the detachable plug 102 is inserted into a complete insertion position until the operating lever 110 is positioned at a falling sidelong position. Consequently, both the pair of terminals 103 and 114 are brought into a completely fitted state. Thus, even when the detachable plug 102 is incompletely inserted into the apparatus body 101, both the pair of terminals 103 and 114 can be prevented from being brought into an incompletely fitted state.
However, the related power circuit breaking apparatus 100, both the terminals 103 and 114 are not in a non-contact state until the operating lever 110 is completely detached from the apparatus body 101. When the operating lever 110 is only rotated from a position, in which the operating lever is pushed sidewise, to another position, in which the operating lever 110 is in an erect state, both the terminals 103 and 114 are still in a contact state. In the case that the lever 110 is returned to a rotation start position notwithstanding the contact state of such terminals, and that a maintenance operation is performed according to the misunderstanding that both the terminals 103 and 114 are in a noncontact state, the safety of operators is not secured. Further, in the power supply breaking apparatus 100, when the operating lever 110 is returned from the position, in which the operating lever 110 is pushed sidewise, to the position, in which the operating lever 110 is in the erect state, the reed switch 107a is turned off. Thus, owing to the turn-off of the reed switch 107a, there is a fear that an operator may misunderstand that both the terminals 103 and 114 are in a noncontact state.
Meanwhile, there have been various kinds of low-voltage small-current connectors adapted to put both terminals into a contact state or a non-contact state by operating a lever in such a way as to perform approaching movement and receding movement of each of both connector housings between a connector temporary fitting position and a connector fitting position. However, in the case of such related connectors, the distance between the terminals in the connector temporary fitting position, which is a movement start position, is not taken into consideration. Thus, when such a related low-voltage small-current connector is applied to a high-voltage large-current power circuit breaking apparatus, there is a fear that arc discharge occurs. Thus, the safety of an operation is not ensured.
Accordingly, the invention is accomplished to solve the aforementioned problems, and an object of the invention is to provide a lever-fitting type power supply circuit breaking apparatus adapted to bring terminals of both connector housings, which are placed at a connector temporary fitting position of both connector housings, into a non-continuity state to thereby reliably prevent an occurrence of arc discharge and to thereby ensure the safety of an operator.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A lever fitting type power supply circuit breaking apparatus comprising:
a first connector provided with a terminal;
a second connector provided with a terminal;
a lever movably provided on the first connector;
a cam groove provided on one of the lever and the second connector; and
a cam pin provided on the other of the lever and the second connector and adapted to be engaged with the cam groove,
wherein in a connector temporary-fitting position, the first connector is fitted to the second connector and the terminal of the first connector is separated from the terminal of the second connector by 0.5 mm or more, in a connector fitting position, the first connector is fitted to the second connector and the terminal of the first connector is electrically connected to the terminal of the second connector, and
wherein the cam pin is moved along and guided by the cam groove so as to shift the first and second connector from the connector temporary-fitting position to the connector fitting position as the lever is shift from a movement start position to a fitting completion position.
(2) The lever fitting type power supply circuit breaking apparatus according to (1), wherein
the lever performs rotational movement between the movement start position in which the terminals of the first and second connectors are separated from each other and a rotation completion position in which the terminals of the first and second connectors are brought in electrical contact with each other, and rectilinear movement between the rotation completion position in which a fitting detection switch is in off state and the fitting completion position in which the fitting detection switch is in on state, and
a power supply circuit is connected in series to a relay circuit which is turned on and off by the fitting detection switch, and a power switch comprising the terminals of the first and second connector housings.
In this lever fitting type power supply circuit breaking apparatus, during both the connectors are placed at a connector temporary-fitting position, the terminals of both the connector housings are disposed by putting a certain distance therebetween, which is sufficient for preventing an occurrence of arc discharge. Consequently, an occurrence of arc discharge between the terminals of both the connector housings is reliably prevented. Thus, the safety of an operator is ensured.
In the case of the second lever fitting type power supply circuit breaking apparatus, even when a failure of the power supply circuit (or electric circuit) is caused and the relay circuit is not normally turned off by breakdowns of the fitting detection switch and the relay circuit in an operating process in which the lever rectilinearly moves from the fitting completion position to the rotation completion position, an occurrence of arc discharge between the terminals of both the connector housings is reliably prevented because the terminals of both the connector housings are separated away by a certain distance therebetween, which is sufficient for preventing an occurrence of arc discharge, during both the connector housings are placed at the connector temporary-fitting position. That is, the power supply circuit is interrupted only by operating the lever. Thus, the safety of an operator is ensured.